Energy stores and systems

System = object or group of objects

What are the 5 main energy stores?

Gravitational potential, kinetic, chemical, elastic potential and thermal

The law of the conservation of energy:

Energy cannot be created or destroyed - it is only transferred from one store to another.

An isolated system is called a closed system. There are no energy transfers into or out of a closed system, only within it. This is why the total energy of a closed system does not change.

Work is done on an object when it is moved by a force

Difference between weight and mass?

Mass is a measure of how much matter makes up an object, measured in kg.

Weight is a measure of how much force an object presses down with, and is caused by gravity, measured in newtons.

100 degrees celsius is the boiling point of water.

• Useful energy is energy in the place we want it and in the form we need it.
• Wasted energy is the energy that is not useful and is transferred by an undesired pathway.
• Wasted energy is eventually transferred to the surroundings, which become warmer.
• As energy dissipates, it gets less and less useful.